# coding:utf-8
import os
import math
import random
import numpy as np
from PIL import Image, ImageDraw, ImageFont, ImageFilter
 
# abcdefghjkmnpqrstuvwxy
_letter_cases = "abdefghmnpqrstvwxyz" # 小写字母，去除可能干扰的c i j k l o u v
_upper_cases = "ABDEFHMNPQRSTWXYZ" # 大写字母，去除可能干扰的C G I J K L O U V 
_numbers = ''.join(map(str, range(2, 10))) # 数字，去除0，1
init_chars = ''.join((_letter_cases, _upper_cases, _numbers))
fontType = "./luxirb.ttf"
bg_image = "./background.jpg"
out_dir = "./mycaptchas"

def create_validate_code(size=(96, 25),
                             chars=init_chars,
                             img_type="jpg",
                             mode="RGB",
                             bg_image=bg_image,
                             fg_color=(255, 255, 255),
                             font_size=20,
                             font_type=fontType,
                             char_length=6,
                             draw_lines=True,
                             n_line=(10, 16),
                             min_length=1,
                             max_length=12,
                             draw_points=False,
                             point_chance = 2):
  '''
  @todo: 生成验证码图片
  @param size: 图片的大小，格式（宽，高），默认为(120, 30)
  @param chars: 允许的字符集合，格式字符串
  @param img_type: 图片保存的格式，默认为GIF，可选的为GIF，JPEG，TIFF，PNG
  @param mode: 图片模式，默认为RGB
  @param bg_color: 背景颜色，默认为白色
  @param fg_color: 前景色，验证码字符颜色，默认为白色#FFFFFF
  @param font_size: 验证码字体大小
  @param font_type: 验证码字体，默认为 ae_AlArabiya.ttf
  @param length: 验证码字符个数
  @param draw_lines: 是否划干扰线
  @param n_lines: 干扰线的条数范围，格式元组，默认为(1, 2)，只有draw_lines为True时有效
  @param min_length: 干扰线的最小长度
  @param max_length: 干扰线的最大长度
  @param draw_points: 是否画干扰点
  @param point_chance: 干扰点出现的概率，大小范围[0, 100]
  @return: [0]: PIL Image实例
  @return: [1]: 验证码图片中的字符串
  '''
 
  width, height = size # 宽， 高
  img = Image.open(bg_image) # 创建图形
  draw = ImageDraw.Draw(img) # 创建画笔
  if draw_lines:
    create_lines(draw,min_length,max_length,n_line,width,height)
  if draw_points:
    create_points(draw,point_chance,width,height)
  strs = create_strs(draw,chars,char_length,font_type, font_size,width,height,fg_color)
  # # 图形扭曲参数
  # params = [1 - float(random.randint(1, 2)) / 100,
  #           0,
  #           0,
  #           0,
  #           1 - float(random.randint(1, 10)) / 100,
  #           float(random.randint(1, 2)) / 500,
  #           0.001,
  #           float(random.randint(1, 2)) / 500
  #           ]
  # img = img.transform(size, Image.PERSPECTIVE, params) # 创建扭曲
  img = img.filter(ImageFilter.DETAIL) # 滤镜，边界加强（阈值更大）
  return img, strs

 
 
def create_lines(draw,min_length,max_length, n_line, width, height):
  '''绘制干扰线'''
  line_num = random.randint(n_line[0],n_line[1]) # 干扰线条数
  for i in range(line_num):
    # 起始点
    begin = (random.randint(0, width), random.randint(0, height))
    # 长度
    length = min_length+random.random()*(max_length-min_length)
    # 角度
    alpha = random.randrange(0, 360)
    #结束点
    end = (begin[0]+length*math.cos(math.radians(alpha)),
          begin[1]-length*math.sin(math.radians(alpha)))
    draw.line([begin, end], fill=(255, 255, 255))
 
def create_points(draw,point_chance,width,height):
  '''绘制干扰点'''
  chance = min(100, max(0, int(point_chance))) # 大小限制在[0, 100]
  
  for w in xrange(width):
    for h in xrange(height):
      tmp = random.randint(0, 100)
      if tmp > 100 - chance:
        draw.point((w, h), fill=(0, 0, 0))
 
def create_strs(draw,chars,char_length,font_type, font_size,width,height,fg_color):
  '''绘制验证码字符'''
  '''生成给定长度的字符串，返回列表格式'''
  # c_chars = random.sample(chars, length) # sample产生的是unique的char
  flag = False
  while not flag:
    c_chars = np.random.choice(list(chars), char_length).tolist()
    strs = ''.join(c_chars) # 每个字符前后以空格隔开
    
    font = ImageFont.truetype(font_type, font_size)
    font_width, font_height = font.getsize(strs)
    
    try:
      start_x = random.randrange(0, width - font_width)
      start_y = random.randrange(0, height - font_height)
    except ValueError as e:
      print e
      print strs
      print width, font_width, height, font_height
    else:
      flag = True

  draw.text((start_x, start_y), strs, font=font, fill=fg_color)
  return ''.join(c_chars)
 
 
if __name__ == "__main__":
  if not os.path.exists(out_dir):
    os.makedirs(out_dir)
  for _ in range(500):
    code_img, code_str = create_validate_code()
    code_img.save("%s/%s.jpg" % (out_dir, code_str))